The nanoimprinting technique is a technique for transferring a template pattern formed on a surface of a template to a resist on a substrate. The resist is, for example, photo-curable resin such as a UV-curable material.
In the nanoimprinting, the template is pressed against the resist on the substrate and the template pattern is filled with the resist. The resist in the pattern is cured and then the template is released from the substrate. This forms an uneven pattern (recess/protrusion pattern) on the resist on the substrate.
If, however, the substrate has a large step difference (topography), the followability of the template near the step difference is low, in which case the pattern defect may be caused. In addition, if the topography is large, the thickness of the resist (called RLT) between the template and the substrate varies to increase the shearing force of the template. The variation in thickness of RLT has an influence on the alignment. As a result, the overlapping accuracy between the substrate and the imprint pattern is deteriorated. If the step difference of the substrate is large in the light exposure, the focusing position within the shot is different above and below the step difference, in which case the patterning defect is caused.
For planarizing the step difference of the substrate, a planarizing technique such as forming an applied film has been suggested. However, the planarization for the step difference in the nanoscale has been insufficient.